Hi dolmen,
Thanks for creating a great utility to make Git interaction with Github secure!
When I specified the comment (via -C argument) for my key on the comment line, it was not passed through to the underline ssh-keygen command.
I digged into the code and found that the key comment is hard-coded at https://github.com/dolmen/github-keygen/blob/release/github-keygen#L9447
My workaround is to specify my comment string at https://github.com/dolmen/github-keygen/blob/release/github-keygen#L9452 :)
I don't know about Perl so I cannot do a proper fix. :(.